Atriplex nummularia

Old Man Saltbush

Botanical Name: Atriplex nummularia
Family: Amaranthaceae
Origin: Inland and coastal Australia (widespread native to SA)
Plant Type: Hardy evergreen shrub

Overview

A robust, long-lived Australian native shrub prized for its silvery-grey foliage, exceptional drought and salt tolerance, and versatility in South Australian landscapes. Naturally occurring across semi-arid inland regions and coastal fringes, Atriplex nummularia thrives in Adelaide’s hot, dry climate and poor, alkaline soils. Excellent for use as a windbreak, habitat shrub, erosion stabiliser, or hardy grey foliage contrast, it’s ideal for low-maintenance, waterwise and native gardens throughout SA.

Key Features

• Mature Size: 2–3 m H × 2–4 m W (broad, rounded habit)
• Growth Rate: 20-50 cm per year under good conditions
• Foliage: Evergreen; dense, silver-grey, oval leaves with a distinctive sheen that reflects heat and light
• Flowers: Small, yellowish-green clusters appearing in spring–summer (not showy)
• Seasonal Interest: Year-round silvery-grey foliage provides consistent structure and contrast; occasional seasonal flower clusters add subtle texture
• Wildlife Value: Important native habitat and food source for small birds, insects, and lizards; dense structure provides excellent nesting and wind protection
• Tolerance: Extremely drought- and heat-tolerant once established, very high salt and wind tolerance (front-line coastal and inland saline sites), tolerates light frost and harsh inland exposure
• Planting Density: Shelterbelt / Hedge: 1–1.5 m apart; Mass Planting: 1.5–2.5 m apart for open, natural effect
• Pet Friendly: Non-toxic to cats and dogs; safe for family and habitat gardens

Where It Works Best

• Sunlight: Full sun (essential for dense growth and best foliage colour)
• Soil: Sandy, gravelly, or clay loam; tolerates saline or alkaline soils common in SA regions
• Water Needs: Establishment: 1-2 deep soaks/week for 8–12 weeks. Established: deep soak every 3–4 weeks in summer (weekly in heatwaves); minimal in winter
• Maintenance: Very low maintenance. Light tip prune or trim annually to maintain shape and prevent legginess. Avoid rich fertilisers—thrives in lean soils. Mulch to suppress weeds and conserve moisture
• Lifespan: 20–30+ years under SA conditions; long-lived and self-sustaining once mature
• Climate Zones: Mediterranean, semi-arid, and coastal South Australia — thrives from the Adelaide Plains to Yorke, Eyre, and upper Spencer Gulf regions
• Soil pH: Tolerates a wide range — from neutral to strongly alkaline or saline soils

Landscape & Design Ideas

• Coastal and inland shelterbelts or windbreaks
• Hardy grey contrast in native or drought-tolerant gardens
• Mass planting for erosion control and soil stabilisation on sandy sites
• Informal hedging in coastal suburbs or rural properties
• Excellent companion for blue-grey and silver-foliage palettes (e.g., Eremophila, Westringia, Lomandra)

Why You Will Love It

Tough, resilient, and uniquely silvery, Atriplex nummularia thrives in Adelaide’s dry climate and poor soils, bringing dependable structure, native habitat value, and year-round beauty to low-maintenance gardens across South Australia.